How to check if Hadoop daemons are running?

Question

What are simple commands to check if Hadoop daemons are running?

For example if I\'m trying to figure out why HDFS is not setup correctly I\'ll want to know a way to ch

Answer 1

apart from jps, another good idea is to use the web interfaces for NameNode and JobTracker provided by Hadoop. It not only shows you the processes but provides you a lot of other useful info like your cluster summary, ongoing jobs etc atc. to go to the NN UI point your web browser to "YOUR_NAMENODE_HOST:9000" and for JT UI "YOUR_JOBTRACKER_HOST:9001".